Predictive and prognostic value of circulating endothelial cells in non-small cell lung cancer patients treated with standard chemotherapy.

PURPOSE: Monitoring circulating endothelial cells (CECs) count reflects the tumor vasculature in cancer patients and might be a predictor of response to chemotherapy. We therefore investigated the clinical significance of changes in CECs count after three cycles of platinum-based chemotherapy in patients with advanced non-small cell lung cancer (NSCLC). METHODS: Peripheral blood samples were collected from 89 naive NSCLC patients at diagnosis and after chemotherapy. The CECs were quantified by an immuno-magnetic technique and fluorescent microscopy. After chemotherapy, patients were assessed according to the response evaluation criteria in solid tumors as partial response (PR), stable disease (SD) or progression disease (PD). RESULTS: Baseline CECs levels were significantly higher in PR patients (n = 62) than those in patients with SD/PD (n = 27) (p = 0.0007). Although there was no significant correlation between baseline CECs levels and progression-free survival (PFS) (p = 0.287), patients with high percentage change in CECs count after chemotherapy had significantly longer PFS than those with low percentage change (p = 0.048). Regarding treatment efficacy, CECs count significantly decreased after chemotherapy in comparison with CECs count at baseline in patients with PR (p < 0.0001). By contrast, CECs levels after chemotherapy were significantly higher than those at diagnosis in patients with PD (p = 0.002). Moreover, there was no significant change between pre- and post-treatment CECs amount in patients with SD (p = 0.681). CONCLUSIONS: Baseline CECs levels might be an early predictive biomarker for treatment efficacy in advanced NSCLC patients. Our results suggest the change in CECs count after chemotherapy as a prognostic factor for tumor response and PFS in NSCLC.